Cut-off valve for fluid-supply pipes



(No Model.)

P. MOORE.

GUT-OFF VALVE FOR FLUID SUPPLY PIPES. I No. 361,884. Patented Apr. 26, 1887.

{In I my L IHI' II II I '31 UNITED STATES PATENT OFFICE) V FRANK MOORE, or PITTSBURG, PENNSYLVANIA CUT-OFF VALVE FOR FLUlD-SUPPLY PIPES.

SPECIFICATION forming part of Letters Patent No. 361,884, dated April 26, 1887.

Application filed November 23, 1886. Serial No. 219,596. (No model.)

To all whom it may concern.-

Be it. known that I, FRANK MOORE, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvements in Out- Otf Valves for Fluid-Supply Pipes, of which improvements the following is a specification.

The object of my invention is to provide a cut-off device of simple and inexpensive construction which will admit of the passage of fluid through a pipe at or above any desired minimum normal pressure however low and which will automatically shut off the supply of fluid immediately upon a reduction ofpressurein thepipebelow the determined minimum.

To this end my invention, generally stated, consists in the combination,with afluid-supply pipe, of a cut-off valve governing the passage of fluid through said pipe, a pressure-chamber communicating with the supply-pipe on each side of the cut-oft'valve,and a stem working in the pressurechamber and coupled to the out off valve, said stem carrying two movable pressure-disks of unequal areas which are respectively subject to the pressure of fluid from the supply and the delivery sides of the cut-off valve; also, in the combination,with a cut-off device as above specified, of a bypass valve for theadmission of fluid to the delivery-compartment of the pressure-chamber.

The improvements claimed are hereinafter fully set forth.

In the accompanying drawings, Figure 1 is a view in elevation of a fluid-supply cut-off valve embodying my invention; Fig. 2, a vertical longitudinal central section through the same, and Fig. 3 a central section through the bypass valve-chamber.

In the practice of my invention I provide a cylindrical case or valve-chest, 1, having a supply opening or passage, 2,anda delivery-opening, 3, at its opposite ends, which are threaded or otherwise suitably adapted for connection to adjacent sections of afluid-supply or service pipe, so that the case 1 may form part of the line of traverse of fluid through the same. A cut-off valve, 4, secured upona stem, 5, con trols a central opening in a partition, 6, extending across the case 1, and is adapted to close or seat by' movement in the direction of the delivery of fluid upon a valve-face formed around the opening of thepartitionG. A pressure-chamber, 7, which is closed at top by alid or cap, 8, is cast integral with or secured to the case 1, the upperportion of said chamber commu nicat-ing with the case 1 by a passage, 9, on the supply side of the cut-off valve 4, and its lower portion communicating with the case by a passage, 10, 011 the delivery side of the cut 6c off valve. A stem, 11, fitted to move freelyin a Vertical plane in the pressure-chamber 7, is secured centrally to two movable pressuredisks, 12 13, of. unequal areas, respectively, which may be either properly-packed pistons or, preferably, as shown-flexible diaphragms secured at their peripheries to the pressurechamber 7 between the openings thereinto of the fluid-pressure.supply-passages 9 and 10. The stem 11 is coupled to the cut-off-valve stem 5 by a bell-crank or double-armed lever, 14, pivoted to the casing 1, one arm of the lever being connected by a pin to the lower end of the stem 11 and the other having curved faces fitting in a slot in the valve-stem 5. Under such construction it will beseen that downward movement of the diaphragm-stem 11 acts to close andupward movement to open the cut-off valve 4. A bypass valve, 15, secured upon a stem, 16, governs a passage, 17, extending from a chamber, 18, on the side of the case 1 to the interior of the case 1 on the delivery side of the cutoff valve 4, the by-pass chamber communicating with the case on the supply side of the valve by an open port or 8 passage, 19. The by-pass valve is held to its seat so as to be normally closed by a spring,

20, and its stem 16, which passes freely through an opening in the outer end of the chamber,is inclosed by'a removable screw-cap, 21.

In operation, lluid enters the pressure-ehamher 7' above the smaller diaphragm,12,by the passage 9,and its pressure upon the diaphragm 12 and cut-off valve, superadded to the gravity of the stem 11 and diaphragms 12 13,closes ()5 the cut-off valve 4. Fluid-pressnreis then admitted to the chamber 7 below the larger diaphragm,13,by removing the cap 21 of the bypass valve and holding the latter away from its seat until the excess of "upward pressure 102 upon the larger area of the diaphragm 13 raises the stem 11, and thereby, through the lever 14 and valve-stem 5, opens the cut-ofl valve, when the bypass valve is allowed to return to its seat and the cap 21 is replaced.

The out-off valve will then remainvopen for the passage of fluid until the pressure in the supply-pipe and case 1 falls below the normal 5 and determined minimum, at which period the gravity of the stem 11 and its diaphragms,be-

ing no longer balanced by an equivalent upward pressure,will effect the downward movement of the stem 11, andthereby close the cutoff valve 4 and shut off the supply of fluid to the delivery end offthe case .1. and the pipe which is connected thereto.

I am aware that a regulating and cut-off valve, a disk or pair of disks subject to fluid- 15 pressure and connected to a cut-off valve, and

a bypass valve for intermittently effecting the traverse of fluid from one side to the other of a cut-off valve were severally known in the art at the date of myinvention. Instances of such devices and ofcombinationsthereof,which I hereby disclaim, are exemplified in the patents of George \Vestingliouse,Jr.,No. 324,905, August 25, 1885, and No. 341,295, May 4, 1886, as well as in others with which I'am familiar; but, so far as my knowledge and information extend, no structure has heretofore been proposed or employed in which variation of fiuid pressure upon adifferential-pressure device has been utilized to effect the closure of acutoff valve, as in my invention. 7

I claim as my invention and desireto secure by Letters Patent 1. The combination of a cut-off valve controlling the passage of fluid between supply and delivery pipes, a pressure-chamber communicating with said pipes, and a differential piston or diaphragm pressure device fitted to move in the pressurechamber and coupled to the cut-off valve in position to close the same 0 by a reduction of pressure upon the larger member of the pressure device below a determined minimum, substantially as set forth.

2. The combination of avalve-case, a cut-off valve governing the passage of fluid through the same, a pressure-chamber communicating with the valve-case by passages on each side of the cut-off valve, and an actuating-stem fixed to two movablepressure-disks of unequal areas working in said pressure-chamber be" tween the passages leading to the valve-case and coupled to the cut-off-valve stem,substantially asset forth.

3. The combination of a fluid-pressure cutoff valve, a differential piston or diaphragm pressure device coupled thereto, and a handoperated bypass valve controlling the passage of fluid from the supply to the delivery side of the cut-off valve, substantially as set forth.

4:. The combination of a valve-case, acut-off valve governing the passage of fluid between supply and delivery openings at opposite ends of the case, a pressure-chamber communicating with the case at its upper and lower ends by passages on the supply and delivery sides of the cut-off valve,respectively, a stemwork ing vertically in the pressure-chamber and secured to two pistons or diaphragms of unequal areas working inthe pressure-chamber between the passages leading to the valve-case, a bell-crank lever coupling the diaphragnr stem and the cut-ofi-valve stem,"and a handoperated by-pass valve governing communication between the supply and delivery sides of the cut-off valve, substantially as set forth.

In testimony whereof I have hereunto set 7 5 my hand.

j FRANK MOORE. Vitnesses:

J. SNoWDEN BELL, R. H. WVHITTLEsEY. 

